Mini fan mounting arrangement

ABSTRACT

A mini fan mounting arrangement in which the stator has an annular locating flange at the center of the top insulation frame thereof, and the fan blade assembly has a plurality of springy hooks equiangularly spaced around the center shaft thereof and respectively hooked in the annular locating flange to secure the fan blade assembly to the stator for enabling the fan blade assembly to be rotated on the stator.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to mini fans and, more specifically, to a mini fan mounting arrangement.

[0003] 2. Description of the Related Art

[0004]FIG. 1 is an exploded view of a mini fan for use in a computer for cooling. The mini fan comprises a fan blade assembly 10, an axle bearing 11, a stator 12, a circuit board (not shown) fixedly mounted in the stator 12, a casing 14, and a C-shaped clamp 15. The fan blade assembly 10 comprises a shaft 101. The fan shaft 101 having a locating groove 102 around the periphery near the distal end. The casing 14 has an axle sleeve 141 for supporting the stator 12. The axle bearing 11 is mounted in the axial hole 142 of the axle sleeve 142 to support the shaft 101 of the fan blade assembly 10. The C-shaped clamp 15 has an inner diameter 151 slightly smaller than the outer diameter of the shaft 101 but greater than the diameter of the locating groove 102. When assembling the mini fan, the stator 12 is mounted on the axle sleeve 141 of the casing 14, and then the axle bearing 11 is press-fitted into the axial hole 142 of the axle sleeve 141, and then the shaft 101 of the fan blade assembly 10 is inserted through the axle bearing 11, and then the C-shaped clamp 15 is fastened to the locating groove 102 of the shaft 101 to secure the fan blade assembly 10 to the axle bearing 11 and the casing 14. FIG. 2 shows the mini fan assembled. This assembly process requires a special tool to fix the C-shaped clamp 15 to the locating groove 102 of the shaft 101. Because the inner diameter 151 of the C-shaped clamp 15 slightly smaller than the outer diameter of the shaft 101 but greater than the diameter of the locating groove 102, the C-shaped clamp 15 must be greatly deformed before fastening to the locating groove 102. The use of the C-shaped clamp 15 complicates the assembly procedure of the mini fan and, relatively increases the manufacturing cost of the mini fan.

SUMMARY OF THE INVENTION

[0005] The present invention has been accomplished to provide a mini fan mounting arrangement, which eliminates the aforesaid drawbacks. It is therefore the main object of the present invention to provide a mini fan mounting arrangement, which greatly simplifies the assembly process of the mini fan, improving the productivity. According to the invention, the stator has an annular locating flange at the center of the top insulation frame thereof, and the fan blade assembly has a plurality of springy hooks equiangularly spaced around the center shaft thereof and respectively hooked in the annular locating flange to secure the fan blade assembly to the stator for enabling the fan blade assembly to be rotated on the stator. Because the invention eliminates the use of a C-shaped clamp to secure the fan blade assembly to the casing, the assembly process of the mini fan is easy.

[0006] The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

[0007] Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is an exploded view of a mini fan according to the prior art.

[0009]FIG. 2 is a sectional assembly view of the mini fan according to the prior art.

[0010]FIG. 3 is an exploded view of a part of the present invention.

[0011]FIG. 4 is a sectional exploded view of the present invention.

[0012]FIG. 5 is a sectional assembly view of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

[0014] Referring to FIGS. 3 and 4, a mini fan mounting arrangement in accordance with the present invention is shown comprised of a fan blade assembly 2, a stator 3, a circuit board 5, an axle bearing 6, and a casing 4. The fan blade assembly 2 has a motor housing 21 and a permanent magnet 22 provided on the inside, a shaft 23 suspended on the center, and a plurality of springy hooks 24 equiangularly spaced around the shaft 23. The hooks 24 each have an outer end terminating in a hooked portion 241.

[0015] The stator 3 is comprised of silicon steel sheets 31, top and bottom insulation frames 32 and 33, and a winding 34. The circuit board 5 is fixedly fastened to one side of the stator 3. The top insulation frame 32 has an annular locating flange 321 at the center for receiving the hooks 24.

[0016] The casing 4 has an axle sleeve 41 for supporting the stator 3. The axle sleeve 41 defines an axial hole 411 fitting the outer diameter of the axle bearing 6.

[0017] Referring to FIG. 5 and FIGS. 3 and 4 again, the stator 3 is mounted on the axle sleeve 41 inside the casing 4, and then the axle bearing 4 is press-fitted into the axial hole 411 of the axle sleeve 41, and then the shaft 23 of the fan blade assembly 2 is inserted through the axle bearing 6 into the center of the stator 3 to force the hooked portions 241 of the hooks 24 into engagement with the annular locating flange 321 of the stator 3. When forcing the hooks 24 against the locating flange 321, the hooks 24 are radially inwardly compressed, for enabling the hooked portions 241 to pass through the inner diameter of the annular locating flange 321. When passed, the springy material property of the hooks 24 forces the hooks 24 to return to their former shape, thereby causing the hooked portions 241 firmly hooked on the annular locating flange 321, and therefore the fan blade assembly 2 and the stator 3 are coupled together.

[0018] As indicated above, the invention has the following advantages:

[0019] 1. The hooks of the fan blade assembly and the annular locating flange of the stator form a hook joint, enabling the mini fan to be rapidly assembled.

[0020] 2. Because the invention eliminates the use of a C-shaped clamp to secure the shaft of the fan blade assembly to the casing as the prior art design does, the mini fan manufacturing cost is greatly reduced.

[0021] A prototype of mini fan mounting arrangement has been constructed with the features of FIGS. 3˜5. The mini fan mounting arrangement functions smoothly to provide all of the features discussed earlier.

[0022] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

[0023] While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 

I claim:
 1. A mini fan mounting arrangement comprising a casing, said casing having a center axle sleeve, a stator mounted on said axle sleeve inside said casing, an axle bearing press-fitted into said axle sleeve, and a fan blade assembly mounted within said casing, said fan blade assembly having a center shaft supported in said axle bearing, wherein said stator has an annular locating flange at the center of a top insulation frame thereof; said fan blade assembly comprises a plurality of springy hooks equiangularly spaced around said center shaft and respectively hooked in said annular locating flange.
 2. The mini fan mounting arrangement as claimed in claim 1 wherein said spring hooks are respectively inserted into said annular locating flange, each having an outwardly protruded hooked portion respectively hooked on said annular locating flange. 